infix astid 2-9 avgturn 11-20 cntl 22-25 turnl 28-36 retl 38-46 cnth 48-51 turnh 54-62 reth 64-72 using "e:\FIS\rets_high_low_vol_easy_borrow_rep.txt"
summarize reth retl avgturn turnh turnl cnth cntl
gen difret = reth-retl
ttest difret == 0